The3P0‐3H6(1) transition of Pr in PrF3was observed to undergo laser action under direct pulsed excitation at low temperature with a high conversion efficiency. Comparison with such behavior in other types of material is made and the usefulness of this stimulated emission behavior as a spectroscopic tool in characterizing concentrated materials is discussed. The parameters describing threshold conditions, linewidths, and energy conversion are measured and compared to theory.